Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2305.15662 · Physical Review Applied

Phase-controlled improvement of photon lifetime in coupled superconducting cavities

Changqing Wang, Oleksandr Melnychuk, Crispin Contreras-Martinez, Yao Lu, Yuriy Pischalnikov, Oleg Pronitchev, Bianca Giaccone, Roman Pilipenko, Silvia Zorzetti, Sam Posen, Alexander Romanenko, Anna Grassellino

Published Feb 21, 2024• 3 citations
arXivHTMLPDF

Abstract

High-quality cavities are crucial for various fundamental physical studies and applications. Here we find that by coupling two cavities directly or via a phase-tunable coupling channel, the photon lifetime of the local field can exceed that of the bare cavities. The cavity photon lifetime is modified by the phases of the initial states and the phase accumulation on the coupling channel, which affect the interference between cavities. In experiments, by coupling superconducting radio-frequency cavities via phase-tunable cables, we realize a factor of 2 improvement in the cavity photon lifetime. The results can bring rich revenue to quantum information science, sensing, and high-energy physics.

DOI
10.1103/physrevapplied.21.024040

Related papers

Phase-controlled enhancement of photon lifetime in coupled superconducting cavities.

Changqing Wang

The photon lifetime of superconducting cavities is essential forthe long coherence of quantum computing units and sensors. Wediscover that the photon lifetime of cavity field in a couple- cavitysystem is modified by the phases of the initial states and thephase in the coupling channel. Experimentally by performingring-down measurement for two coupled 3D superconductingcavities, we observed a factor of two enhancement in cavityphoton lifetime. The result open new avenues for improvingperformances of superconducting cavities and quantum systems.

•Nov 22, 2023•0 citations

Reaching 10 ms single photon lifetimes for superconducting aluminum cavities

Matthew Reagor, Hanhee Paik, Gianluigi Catelani +10 more

Three-dimensional microwave cavities have recently been combined with superconducting qubits in the circuit quantum electrodynamics architecture. These cavities should have less sensitivity to dielectric and conductor losses at surfaces and interfaces, which currently limit the performance of planar resonators. We expect that significantly (>103) higher quality factors and longer lifetimes should be achievable for 3D structures. Motivated by this principle, we have reached internal quality factors greater than 0.5 × 109 and intrinsic lifetimes of 0.01 s for multiple aluminum superconducting cavity resonators at single photon energies and millikelvin temperatures. These improvements could enable long lived quantum memories with submicrosecond access times when strongly coupled to superconducting qubits.

arXiv:1302.4408•Applied Physics Letters•May 13, 2013•212 citations

Superconducting radio frequency cavities for parametric amplification and optomechanics

Alessandro R. Castelli

Superconducting radio frequency (SRF) cavities present a unique opportunity in their potential for extremely large quality factors (Q) which allow for low-loss microwave systems which extend photon lifetimes. They have subsequently been used and improved upon as individual cells of particle accelerators where large accelerating voltages are required. More recently, they have been used as double SRF cavity systems for coupling electromagnetic fields via qubits inserted into the cavity bodies. Capitalizing on this Q enhancement, we propose an SRF cavity system for parametric amplification of these microwave fields from vacuum. This triple SRF cavity consists of a pump cavity with a silicon nitride (SiN) membrane acting as one end-wall and two signal/idler cavities that are separated by an iris plane. Parametric amplification occurs when some parameter of the system varies sinusoidally in time and this subsequently drives the system into oscillation. Here, we vary the length of the cavities by driving the SiN membrane end-wall into motion using the radiation pressure from the pump cavity. Sufficient energy transfer between cavities will allow amplification and subsequent oscillation of the vacuum fields. We will introduce and explain theoretical background, SRF cavity fabrication and testing, SiN membrane mechanics, and lastly double cavity mechanics. We will identify which facets of the project seem feasible at this time.

•Jan 1, 2018•0 citations

Reaching 10 ms single photon lifetimes for superconducting aluminum cavities

Matthew J. Reagor, Hanhee Paik, Michel Devoret +10 more

Three-dimensional microwave cavities have recently been combined with superconducting qubits in the circuit quantum electrodynamics (cQED) architecture. These cavities should have less sensitivity to dielectric and conductor losses at surfaces and interfaces, which currently limit the performance of planar resonators. We expect that significantly (>10^3) higher quality factors and longer lifetimes should be achievable for 3D structures. Motivated by this principle, we have reached internal quality factors greater than 0.5x10^9 and intrinsic lifetimes of 0.01 seconds for multiple aluminum superconducting cavity resonators at single photon energies and millikelvin temperatures. These improvements could enable long lived quantum memories with submicrosecond access times when strongly coupled to superconducting qubits.

•Jan 1, 2013•166 citations

Three-Dimensional Superconducting Resonators at T<20 mK with Photon Lifetimes up to τ=2 s

A. Romanenko, R. Pilipenko, S. Zorzetti +5 more

Very-high-quality-factor superconducting radio-frequency cavities developed for accelerators can enable fundamental physics searches with orders of magnitude higher sensitivity, and they can also offer a path to a 1000-fold increase in the achievable coherence times for cavity-stored quantum states in three-dimensional circuit QED architecture. Here we report measurements of multiple accelerator cavities of resonant frequencies of ${f}_{0}=1.3$, 2.6, 5 GHz down to temperatures of about 10 mK and field levels down to a few photons, which reveal very long photon lifetimes up to 2 s, while also further exposing the role of the two-level systems (TLS) in niobium oxide. We also demonstrate how the TLS contribution can be greatly suppressed by vacuum heat treatments at 340--450 ${}^{\ensuremath{\circ}}\mathrm{C}$.

arXiv:1810.03703•Physical Review Applied•Mar 12, 2020•194 citations

A direct controlled-phase gate between microwave photons

Adrian Copetudo, Amon M. Kasper, Tanjung Krisnanda +4 more

The rich dynamics and large Hilbert space of quantum harmonic oscillators make them natural candidates for hardware-efficient and error-correctable quantum information processing. However, implementing direct entangling operations between oscillators remains an outstanding challenge. Existing strategies typically rely on parametrically activating interactions that populate the excited states of a nonlinear element, which introduces additional dissipation channels and potential leakage from the encoded manifold. Here, we engineer a Raman-assisted cross-Kerr interaction between microwave photons hosted in two superconducting cavities. Crucially, this dynamics does not excite the mediating nonlinear coupler, thereby suppressing coupler induced decoherence and leakage out of the bosonic code space. We use this direct nonlinear coupling to implement a controlled-phase gate within the single- and two-photon subspaces of two oscillators, deterministically generating entanglement between them. Finally, we use these engineered dynamics to implement a photon-number parity check on a storage cavity via purely bosonic interactions with an ancillary cavity, demonstrating an enhancement in the storage lifetime. Our work provides a promising pathway toward engineering robust operations that act entirely within a protected bosonic code space and realizing fault-tolerant quantum information processing with bosonic elements.

quant-pharXiv:2603.15587•Mar 17, 2026•0 citations
High-quality cavities are crucial for various fundamental physical studies and applications. Here we find that by coupling two cavities directly or via a phase-tunable coupling channel, the photon lifetime of the local field can exceed that of the bare cavities. The cavity photon lifetime is modified by the phases of the initial states and the phase accumulation on the coupling channel, which affect the interference between cavities. In experiments, by coupling superconducting radio-frequency cavities via phase-tunable cables, we realize a factor of 2 improvement in the cavity photon lifetime. The results can bring rich revenue to quantum information science, sensing, and high-energy physics.
The photon lifetime of superconducting cavities is essential forthe long coherence of quantum computing units and sensors. Wediscover that the photon lifetime of cavity field in a couple- cavitysystem is modified by the phases of the initial states and thephase in the coupling channel. Experimentally by performingring-down measurement for two coupled 3D superconductingcavities, we observed a factor of two enhancement in cavityphoton lifetime. The result open new avenues for improvingperformances of superconducting cavities and quantum systems.
Three-dimensional microwave cavities have recently been combined with superconducting qubits in the circuit quantum electrodynamics architecture. These cavities should have less sensitivity to dielectric and conductor losses at surfaces and interfaces, which currently limit the performance of planar resonators. We expect that significantly (>103) higher quality factors and longer lifetimes should be achievable for 3D structures. Motivated by this principle, we have reached internal quality factors greater than 0.5 × 109 and intrinsic lifetimes of 0.01 s for multiple aluminum superconducting cavity resonators at single photon energies and millikelvin temperatures. These improvements could enable long lived quantum memories with submicrosecond access times when strongly coupled to superconducting qubits.
Superconducting radio frequency (SRF) cavities present a unique opportunity in their potential for extremely large quality factors (Q) which allow for low-loss microwave systems which extend photon lifetimes. They have subsequently been used and improved upon as individual cells of particle accelerators where large accelerating voltages are required. More recently, they have been used as double SRF cavity systems for coupling electromagnetic fields via qubits inserted into the cavity bodies. Capitalizing on this Q enhancement, we propose an SRF cavity system for parametric amplification of these microwave fields from vacuum. This triple SRF cavity consists of a pump cavity with a silicon nitride (SiN) membrane acting as one end-wall and two signal/idler cavities that are separated by an iris plane. Parametric amplification occurs when some parameter of the system varies sinusoidally in time and this subsequently drives the system into oscillation. Here, we vary the length of the cavities by driving the SiN membrane end-wall into motion using the radiation pressure from the pump cavity. Sufficient energy transfer between cavities will allow amplification and subsequent oscillation of the vacuum fields. We will introduce and explain theoretical background, SRF cavity fabrication and testing, SiN membrane mechanics, and lastly double cavity mechanics. We will identify which facets of the project seem feasible at this time.
Three-dimensional microwave cavities have recently been combined with superconducting qubits in the circuit quantum electrodynamics (cQED) architecture. These cavities should have less sensitivity to dielectric and conductor losses at surfaces and interfaces, which currently limit the performance of planar resonators. We expect that significantly (>10^3) higher quality factors and longer lifetimes should be achievable for 3D structures. Motivated by this principle, we have reached internal quality factors greater than 0.5x10^9 and intrinsic lifetimes of 0.01 seconds for multiple aluminum superconducting cavity resonators at single photon energies and millikelvin temperatures. These improvements could enable long lived quantum memories with submicrosecond access times when strongly coupled to superconducting qubits.
Very-high-quality-factor superconducting radio-frequency cavities developed for accelerators can enable fundamental physics searches with orders of magnitude higher sensitivity, and they can also offer a path to a 1000-fold increase in the achievable coherence times for cavity-stored quantum states in three-dimensional circuit QED architecture. Here we report measurements of multiple accelerator cavities of resonant frequencies of f0=1.3{f}_{0}=1.3f0​=1.3, 2.6, 5 GHz down to temperatures of about 10 mK and field levels down to a few photons, which reveal very long photon lifetimes up to 2 s, while also further exposing the role of the two-level systems (TLS) in niobium oxide. We also demonstrate how the TLS contribution can be greatly suppressed by vacuum heat treatments at 340--450 ${}^{\ensuremath{\circ}}\mathrm{C}$.
The rich dynamics and large Hilbert space of quantum harmonic oscillators make them natural candidates for hardware-efficient and error-correctable quantum information processing. However, implementing direct entangling operations between oscillators remains an outstanding challenge. Existing strategies typically rely on parametrically activating interactions that populate the excited states of a nonlinear element, which introduces additional dissipation channels and potential leakage from the encoded manifold. Here, we engineer a Raman-assisted cross-Kerr interaction between microwave photons hosted in two superconducting cavities. Crucially, this dynamics does not excite the mediating nonlinear coupler, thereby suppressing coupler induced decoherence and leakage out of the bosonic code space. We use this direct nonlinear coupling to implement a controlled-phase gate within the single- and two-photon subspaces of two oscillators, deterministically generating entanglement between them. Finally, we use these engineered dynamics to implement a photon-number parity check on a storage cavity via purely bosonic interactions with an ancillary cavity, demonstrating an enhancement in the storage lifetime. Our work provides a promising pathway toward engineering robust operations that act entirely within a protected bosonic code space and realizing fault-tolerant quantum information processing with bosonic elements.